Good question! First of all, where are you seeing these listings? If the listing site is fed by the regional listing services (ie: Trulia, Streeteasy, etc) then you shouldn't be seeing New Jersey listings. If you are looking on craigslist, there is little to no regulation to ensure that the info is correct, and many times IT ISN'T! Even on the more trusted sites, there are always mistakes. This is downside self-maintained Real Estate websites. The best thing to do: call them out! I agree, it's very annoying.